Errors that I can't handle

[Porgeyman]

Hey guys so I have had so many errors in the making of my Tekkit server it is unreal I have managed to get passed all of them so far mainly the Groupmanager ones but this on is driving me crazy. It happens when I type /manuadd to try change my group. If anyone can help please let me know in the comments or via inbox. Thanks George.

[WARNING] Unexpected exception while parsing console command

org.bukkit.command.CommandException: Unhandled exception executing command 'manuadd' in plugin GroupManager v2.0 (2.10.1) (Phoenix)

at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)

at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:166)

at forge.bukkit.ForgeCommandMap.dispatch(ForgeCommandMap.java:55)

at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:497)

at org.bukkit.craftbukkit.CraftServer.dispatchServerCommand(CraftServer.java:493)

at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:625)

at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:593)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:467)

at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)

Caused by: java.lang.NoClassDefFoundError: org/bukkit/command/BlockCommandSender

at org.anjocaido.groupmanager.GroupManager.onCommand(GroupManager.java:394)

at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)

... 8 more

Caused by: java.lang.ClassNotFoundException: org.bukkit.command.BlockCommandSender

at java.net.URLClassLoader$1.run(Unknown Source)

at java.net.URLClassLoader$1.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(Unknown Source)

at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:41)

at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:29)

at java.lang.ClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

... 10 more